Diethyl Ether → Methyl 7-(2,6-dioxocyclohexyl)hept-5-ynoate

HRID 973100Notes

Reaction equation

HRID 973100 reaction equation
[H-].[Na+].[CH2:3]1[CH2:8][C:7](=[O:9])[CH2:6][C:5](=[O:10])[CH2:4]1.Br[CH2:12][C:13]#[C:14][CH2:15][CH2:16][CH2:17][C:18]([O:20][CH3:21])=[O:19].CCOCC>CN(C)C=O>[CH3:21][O:20][C:18](=[O:19])[CH2:17][CH2:16][CH2:15][C:14]#[C:13][CH2:12][CH:6]1[C:7](=[O:9])[CH2:8][CH2:3][CH2:4][C:5]1=[O:10]

Participants

6

Reactant 4

HCID 3283Diethyl EtherHCID 104341,3-CyclohexanedioneHCID 24758Sodium hydrideHCID 11287432Methyl 7-bromohept-5-ynoate

Product 1

HCID 13873492Methyl 7-(2,6-dioxocyclohexyl)hept-5-ynoate

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent3×

Procedure

Sodium hydride (4.2 g) is suspended in dimethylformamide (50 ml) and while stirring the mixture at room temperature, a solution of 3,5-cyclohexanedione (11.2 g) in dimethylformamide (50 ml) is added over a period of 10 minutes. Several minutes later the mixture is cooled to -10° C., and a solution of methyl 7-bromo-5-heptynoate, described in Example 12, in dimethylformamide (50 ml) is added. The reaction mixture is stirred overnight at -10° to -5° C., then ether is added. The mixture is extracted with sodium carbonate. The aqueous extract after acidification with 10% HCl is extracted with ethyl acetate to yield a crude product, which on crystallization from ether affords 7-(2,6-dioxocyclohexyl)5-heptynoic acid methyl ester, m.p. 108° - 110° C, εmaxEtOH 256nm (ε = 14,200).

Workup

  1. temperatureSeveral minutes later the mixture is cooled to -10° C.
  2. additionis added
  3. stirringThe reaction mixture is stirred overnight at -10° to -5° C.
  4. extractionThe mixture is extracted with sodium carbonate
  5. extractionThe aqueous extract after acidification with 10% HCl
  6. extractionis extracted with ethyl acetate
  7. customto yield a crude product, which
  8. customon crystallization from ether

Sources & evidence

ORD record
ord-d81c1a7cb4ce4173852346398141ac94
Source dataset
uspto-grants-1977_10
Patent number
US04054741

Reaction notes

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